As background, there are a number of advantages of using a manually-shifted transmission over an automatic transmission in vehicles. First, manual transmissions cost less to manufacture than comparable automatic transmissions. Second, manual transmissions weigh less than automatic transmissions, thus improving fuel economy and handling. Finally, even in the absence of any weight advantage, manual transmissions generally have better fuel economy than automatic transmissions.
Conventional manual transmissions also have some drawbacks. For example, during the assembly of a vehicle with a manual transmission, the mechanical linkage between the shifter and the shift forks may require adjustment in order to compensate for component and/or manufacturing variations. In addition, the mechanical linkage between the clutch pedal and the clutch may also require adjustment for the same reason. These adjustments ensure that both the shifter and the clutch pedal will operate properly when the vehicle is subsequently delivered to the customer. The adjustments to the mechanical linkages during manufacturing may be costly in terms of both labor and the time required to make the adjustment.
Accordingly, a need exists for alternative manual transmission systems which may be electronically shifted without mechanical linkages between the shifter and the shift forks as well as between the clutch pedal and the clutch.